Method and apparatus for cooling clinker



March 5, 1963 B. HELMING EI'AL 3,079,701

A mom AND APPARATUS FOR COOLING CLINKER Filed April 3, 1958 2 Sheets-Sheet 1 w & \E

\ n [A k 3/ l I J 2 D D D 2 y I 1 3 umummmummmmnllifim INVENTORS JEI'MJY8ZWZ% WIAMM, KM Y ATTORNEYS March 5, 1963 B. HELMING EI'AL 3,079,701

METHOD AND APPARATUS FOR cooLmc CLINKER Filed April 3, 1958 2 Sheets-Sheet 2 ATTORNEYS- United States Patent Bernd Helm'ug, An den Taunen 1, and Wilhelm Braves, Weller-hers! 14, both or Neubeelnnn, Germany Filed Apr. 3, H58, 82:. No. 726,222 8 Claims. rcr. se -57 it is known that cement clinker, i.e,, the granular product of rotary cement furnaces or kilns, may be cooled by means of thrust or traveling grates wherein cooling air is directed from above or below or alternately from both directions through the grates and the clinker disposed thereon to be cooled. The thrust grate has the disadvantage that the grate plates adjacent the discharge end of the furnace are continuously exposed to the very high heat of the glowing clinker and, consequently, are subject to relatively high wear.

Traveling grate clinker coolers, while free of the abovementioned difiiculty by reason of the movement of the grates along the entire length of the cooling apparatus, have not proven satisfactory in practice up to the present time due to irregular deposition of the clinker on the grate, forming partially or wholly clinker-free areas, channels and holes through which the cooling air flows practically without resistance. As the air naturally follows the path of least resistance, the greater portion of it passes through these areas and exerts little or no cooling action on the bulk of the clinker.

These disadvantages are eliminated or at least greatly reduced by the present invention which contemplates the use of a traveling grate, arranged either horizontally or at a sli ht angle, associated with pneumatic means operating in a manner similar to the so-called pneumatic conveyor chutes, whereby the clinker is loosened in the inlet zone of the cooling apparatus by a blast or flow of air of relatively high pressure and is uniformly distributed over the surface of the grate. The pneumatic distributing means may be in the form of a chamber, closed on all sides except at the top, disposed immediately subjacent he path of the grate at or near the inlet end thereof, which chamber extends across substantially the entire width of the grate, along an appreciable portion of its length and is connected to one or more sources of high pressure air. instead of a single chamber, two or more smaller chambers may be arranged side-by-side and two or more chainbers can be arranged end-to-end. The pressure of the air supplied to the individual chambers may be the same or different, as desired. in order to facilitate discharge of the clinker sifting through the grate into the chamber or chambers, the bottom walls thereof are preferably inclined inwardly and downwardly towards a discharge conduit which is provided with an air lock to maintain the air pressure.

Immediately downstream of the distribution means, there can be arranged above the grate a stationary or vertically adjustable gate which serves as battle for the eddied linker and determines the height of the clinker bed.

A preliminary distribution of the clinker coming from the discharge end of the furnace can be efiected by an oscillatable plate-like element; alternatively, this can be accomplished with a vibratory device or the like.

The space above the grate can be subdivided by stationary or vertically adjustable partitions, the use and location of which are dependent upon how the cooling air is to be distributed within the cooler, and what further use is to be made of it. To loosen the bed of clinker on the grate and at the same time agitate and redistribute the clinker, members contacting the top surface of the grate and exerting a hurdle-like action on the clinker can be provided in addition to the pneumatic loosening and distribution means already mentioned.

i atented Mar. 5, 1953 For stirring and turning over the clinker, there can, furthermore, be employed devices in the nature of a plow blade, a I'Einfi, or a rotating ree It is desirable that all of the auxiliary devices which contact the clinker be cooled in some way, as by air, gas or water. They can also be so constructed that air, gas or water can be proec ed through them onto the clinker or into the clinke bed.

it is important that the clinker which drops through the grate comes continuously in contact with cold air, and the design of the cooling system to this end is within the scope of the invention. As the clinker collects at the bottom of the cooler, it can be removed at the center or si es by any desired means, e.g., by screws, pneumatic troughs, vibratory chutes, drag chain conveyors or the like.

in order to crush the clinker which has become sintered or encrusted, it is advisable to install at the discharge end of the cooler a crushing or grinding device, for instance, a sit ing hammer mill or an impeller breaker. The entire clinker or only that part or" it which is in relatively large pieces may be charged into the crushing mill.

One traveling grate clinker cooler constructed in accordance with the invention is shown diagrammatically in the drawings in which:

Flu. l is a cross-sectional view in elevation of the cooler, with the traveling grate indicated by dotted lines;

PEG. 2 is a sectional vi w along line 33 of FIG. 1, showing the mechanism for distributing the clinker onto the grate;

, 1G. 3 is a plan view of the distributing mechanism of 516. 7 is a sectional view along lines 77 of FIG. 1.

Refer "ng to FIG. 1, the burned clinker emerges from the rotary kiln 1 through kiln head 2 which empties at t e The bottom into the inlet chute 3 of the cooler. s of the cooler are constructed, at least for the most part, or" refractory material in the usual manner. The bottom wall of the inlet chute is inclined forwardly and downwardly as at 3a and supports a distributing device generall designated 4-.

The distributing device 4 consists of a tube 5 mounted for oscillatory movement on a block 6, which rests on bottom wall 3a of the inlet chute of the cooler, and a plate '7 of generally rectangular configuration secured he forward end of the tube. The location of plate 7 rrectly below the path of the fall of the clinker emer ing from the discharge end of kiln 1. Tube 5 is of such a length that it extends from this location through the vided therein for this purpose. The portion of tube 5 block 9 and the free end thereof carries a crank 10 by means of which both it and the plate 7 may be oscillated through a linuted arc. The clinker which falls on plate 7 is, or" course, red hot and, preferably, the plate is cooled in some fashion to avoid unduly rapid wear. This may be accomplished by dividing tube 5 longitudinally into two separate passageways, one for the admission and the other for the discharge of cooling air, and forming the plate 7 as a hollow member which is ap propriately partitioned as at ii to guide the cooling air throughout substantially the entirety of the plate. Air or other coolant may be supplied to the tube and discharged therefrom through flexible hoses indicated at 12. By oscillating the distributor, the clinker may be distributed uniformly over the forward portion of the inclined wall 3a, or the plate may be selectively positioned to direct the clinker to a particular area of the wall, as may be desired. To permit the removal of encrusted clinker from the surface of the chute where necessary, one or more access openings 12 may extend through the bottom wall 3a of the chute and the forward wall of the cooler as well, which openings may be sealed in any of the usual ways while the cooler is in use.

7 The bottom wall 3a in inlet chute 3 terminates adjacent the forward end of the upper course of the traveling grate or conveyor which is constructed in any manner customary in the art. This conveyor is indicated by dotted lines and designated by the numeral 15 in FlG. l. Spaced slightly from and above the terminal end of inclined wall 3a is a vertically arranged radiation barrier 16, constructed of refractory material or the like, which has the function of protecting the various devices located behind it from destruction by radiation from the ex tremely hot clinker. One of the devices located behind barrier 16 is a regulator 17 for determining the height of the bed on traveling grate 15. This regulator, as is shown in detail in FIGS. 4 and 5, consists of a large hollow tube 18 extending completely through the cooler and projecting externally of the side walls thereof. Two or more smaller. tube 19 extend laterally from the large tube 18 at spaced points along the length thereof within the confines of the cooler and these branch tubes are connected by a smaller tube extending generally parallel to the large tube 18. One or more vertical plates 21 are suspended from the parallel tube 20 by means of straps or hangers 22. A crank is secured to one of the external ends of the main tube 13, and it will be seen that by moving the crank, tube 18 is rotated to adjust the distance between the lower edge of plate 21 and the upper surface of traveling grate 15. All of the hollow tubes 18, 19 and 20 may be traversed by coolant while the remaining elements of the distributor may be constructed by heat-resistant material.

Below the upper course of the traveling grate adjacent the terminal end of inlet chute 3, there is arranged a pneumatic chamber 25 which is constructed generally in the shape of a hopper, i.e., with an open top and side walls that slope downwardly towards a discharge opening at the center. As shown in FIG. 7, chamber 25 may be divided by longitudinal partitions 26 into two or more compartments and the transverse partitions may also be employed to divide the chamber longitudinally. Each of the compartments which comprise the chamber is in communication with a source of high pressure air through a conduit 2'1, opening through a side Wall thereof. In order that all of the air from the high pressure source will be directed upwardly, the discharge opening is provided with an air seal or air lock and to this end a short conduit 28 is connected to each of the discharge openings 29 and a pair of double swing flaps 39 are arranged therein. Traveling grates of the type contemplated for use in the invention are so constructed as to be readily pervious to the passage of air. The openings in the grate also permit small particles of clinker to sift through, and it is for this reason that the double air lock proves advantageous. As the cooler is used over periods of time, the clinker particles collect in the pneumatic chamber and must be removedin some way. The double air lock makes it possible to discharge the clinker particles from the chamber while the cooler is in operation without appreciable loss in the air pressure within the chamber.

It is, of course, well known that air pressure furnishes a convenient medium for the conveyance of particulate material and the art of pneumatic conveyors is well developed at the present time. It is upon the principle of the. pneumatic conveyor that the pneumatic chamber of the present invention functions. The air under pressure passes through the pervious grate and through the clinker arranged in a bed thereon. in so doing, it lifts the clinker granules and agitates or stirs them over substantially the entire width of the bed. Naturally, this lifting and agitating action occurs randomly so that as a particular area of the bed is moved over the chamber, the clinker is redeposited on the grate with substantial uniform distribution throughout] The pressure of the air necessary to secure this eifect is dependent upon the height of the bed of clinker on the grate and the size of the clinker granules as well. The usual product from cement kilns are moderately small granules, say approximately /s" in diameter, which is well within the capacity of pneumatic conveying devices. It is believed that a person skilled in the art of pneumatic conveying devices will have no difiiculty in arriving at a proper pressure for granules having aparticular size. If desired, the pressure within the individual compartments of the chamber may difier, although, as a general rule, a pressure that is uniform throughout the chamber is more desirable.

In addition to agitating and distributing the clinker, the air from the pneumatic chamber also has a cooling action since it is ordinarily supplied at a temperature lower than that of the heated clinker. However, it is usually necessary to provide for additional cooling of V the clinker as it travels along the length of the grate to the discharge end thereof and this additional cooling may be obtained by sub-dividing the area below the upper course of the grate conveyor into a plurality of zones by means of vertically arranged partitions 33, cooling air being supplied to each of these zones through a conduit 34 with at least one of such conduits for each zone. Any clinker that sifts down through the grate will, of course, come in contact with this air in these zones. v

To insure uniform contact of the cooling air with the clinker on the grate and to prevent the formation of channels in the clinker bed, there are provided downstream of the pneumatic conveyor one or more devices, generally designated 35, which loosen and agitate the bed. As illustrated in FIGS. 1 and 6, these devices may take the form of a triangular shoe 36 supported for swinging movement by one or more arms 37 from a rotatable shaft 38. The shoe is arranged with its acute angle directed upstream, i.e., opposed to the motion of the conveyor, and when adjusted so that the top surface of the grate is just cleared constitutes sort of a hurdle or ramp for the clinker bed, scraping the clinker from the grate, lifting it, turning it over and finally redepositing it on the grate. An additional cooling effect may be obtained by employing a hollow shoe, arm and shaft and passing coolant therethrough. The Walls of the shoe that are not directly contacted by the clinker may be perforated, in which case the coolant is sprayed on the clinker. In lieu of the particular device shown in the drawings, other agitating and stirring devices may be utilized with reasonable effectiveness, such as rotating reels, plows or the like.

The air which has been heated by passage throughthe hot bed of clinker may be utilized to good advantage as combustion air for the kiln, so that the cooler acts as a preliminary heater for the combustion air. The temperature of the clinker, of course, progressively decreases as it moves along the length of the cooler, and towards the discharge end it may lack enough residual heat to raise the temperature of the air in this region to an extent which is necessary for eliicient utilization in the furnace. in order that the relatively highly heated air may be used independently of the cooler air, the area. above the top course of the grate may be dividedinto two zones by a telescoping partition 37, the height of which is adjusted in accordance with the height of the, clinker bed. Thus, air from the region of the hotter zone upstream of partition 37 is passed through the inlet 3 into kiln 1, while air from the downstream part of the housing is discharged to the atmosphere through an outlet 33.

At the end of the traveling grate, the clinker is removed by a scraper 4t and passed onto a stationary grate 41 which may be selected to pass whatever size of material is desired. A crusher 42 is associated with the stationary rate so as to reduce the size of the retained clinker until it too passes through the spacings of the grate. The clinker discharges from the cooler through an outlet 43 onto a conveyor belt 44 by means of which it may be transmitted to any desired point. The discharge opening 43 is preferably equipped with an air lock 45. The stationary grate must occasionally be cleaned and uncrushed material removed therefrom, and for this purpose an access opening 46 is provided in the rear wall of the cooler housing, which opening is sealed by a door 47. The rear wall also includes an inspection hole 48 and a man-hole 49, both of which may be sealed. Where the crusher is arranged above the stationary grate 41 in the vicinity of these various openings, protection for the latter may be afforded by means of an arcuate shield 50.

The fine particles of clinker that pass or sift through the traveling grate will collect on the floor of the cooler housing. To remove this collected clinker, one or more conveyor worms 51 are arranged at the center or along the sides of the cooler, feeding into discharge outlet 43 and thence to conveyor belt 44.

It will be apparent to those skilled in the art that various changes and modifications in design and construction may be made in the embodiment that is illustrated and described without departure from the essence of the invention. Accordingly, the invention is not to be limited to the specific details of the illustrated embodiment but only by the hereunto appended claims.

It is claimed and desired to be secured by Letters Patent:

1. Apparatus for cooling cement clinker or like material in a high capacity kiln plant, comprising a travelling grate arranged in a substantial horizontal direction and upon one end of which the material that is to be cooled is deposited, means to supply cooling air throughout the entire length and breadth of the grate to cool the clinkers, blowing means including a chamber extending across the Width of the grate on the underside thereof for forcing air upwardly through the upper run of the grate in the zone where the material is deposited and at a high pressure and a high velocity that the material is lifted and whirled up in suspension in the air and spread substantially uniformly across the width of the grate.

2. Apparatus according to claim 1, in which means are provided to divide the space under the grate into further chambers, and in which means are provided for supplying cooling air to each further chamber at a pressure differing from that at which air is supplied to the firstmentioned chamber.

3. Apparatus according to claim 1, in which devices are provided above the grate for uniformly spreading the material as to the longitudinal direction of the grate and for adjusting the depth of the bed of material.

4. Apparatus according to claim 1, in which devices are provided above the grate for uniformly spreading the material as to the longitudinal direction of the grate and for adjusting the depth of the bed of material, the devices being provided one after the other in the intended direction of travel of the material on the grate.

5. Apparatus according to claim 1, in which devices are provided above the grate for uniformly spreading the material as to the longitudinal direction of the grate and for adjusting the depth of the bed of material, the devices being provided one after the other in the intended direction of travel of the material in the grate and are adjustable so that a component of movement is in a vertical direction.

6. Apparatus according to claim 1, in which devices are provided above the grate for uniformly spreading the material and for adjusting the depth of the bed of material, the devices having cavities through which a coolant fiuid can be directed.

7. Apparatus for cooling cement clinker or like material in a high capacity kiln plant, comprising a travelling grate arranged in a substantial horizontal direction and upon one end of which the material that is to be cooled is deposited, blowing means extending across the width of the grate on the underside thereof for forcing air upwardly through the upper run of the grate in the zone where the material is deposited and at a high pressure and a high velocity that the material is lifted and whirled up in suspension in the air and spread substantially uniformly across the Width of the grate, devices above the grate for uniformly spreading the material and for ad justing the depth of the bed of material, the devices being provided one after the other in the intended direction of travel of the material on the grate and are adjustable so that a component of movement is in a vertical direction, and said devices having openings which communicate with the cavities and which permit air to be blown on and into the material and water to be sprayed thereon.

8. Apparatus according to claim 1, in which the grate is inclined whereby the material has a downward component of travel.

References Oited in the file of this patent UNITED STATES PATENTS 1,770,409 Kehoe July 15, 1930 1,778,318 Haas Oct. 14, 1930 1,964,878 Hcreng July 3, 1934 2,031,047 Lee Feb. 18, 1936 2,163,513 Douglass June 20, 1939 2,189,120 Ahlmann Feb. 6, 1940 2,862,308 Meredith Dec. 2, 8

FOREIGN PATENTS 50,885 Austria Nov. 29, 1911 238,094 Switzerland Oct. 1, 1945 489,616 France Oct. 15, 1918 

1. APPARATUS FOR COOLING CEMENT CLINKER OR LIKE MATERIAL IN A HIGH CAPACITY KILN PLANT, COMPRISING A TRAVELLING GRATE ARRANGED IN A SUBSTANTIAL HORIZONTAL DIRECTION AND UPON ONE END OF WHICH THE MATERIAL THAT IS TO BE COOLED IS DEPOSITED, MEANS TO SUPPLY COOLING AIR THROUGHOUT THE ENTIRE LENGTH AND BREADTH OF THE GRATE TO COOL THE CLINKERS, BLOWING MEANS INCLUDING A CHAMBER EXTENDING ACROSS THE WIDTH OF THE GRATE ON THE UNDERSIDE THEREOF FOR FORCING AIR UPWARDLY THROUGH THE UPPER RUN OF THE GRATE IN THE ZONE WHERE THE MATERIAL IS DEPOSITED AND AT A HIGH PRESSURE AND A HIGH VELOCITY THAT THE MATERIAL IS LIFTED AND WHIRLED UP IN SUSPENSION IN THE AIR AND SPREAD SUBSTANTIALLY UNIFORMLY ACROSS THE WIDTH OF THE GRATE. 